Chemistry Organic - Things I Don’T Know Yet

Front 1

The molecular ion is both a free radical and an ion.

Back 1

Breaking C-C bonds in alkanes

Front 2

Thermal cracking produces a high percentage of ...?

Back 2

Alkenes

Front 3

Conditions of thermal cracking?

Back 3

• high temp

• high pressure

Front 4

Catalytic cracking produces mainly ...?

Back 4

• cyclic alkanes

• aromatic hydrocarbons

(Used as motor fuels)

Front 5

Conditions of catalytic cracking?

Back 5

• slight pressure

• high temp

• zeolite catalyst

Front 6

Cracking general equation:

Back 6

Back (Definition)

Front 7

Write two equations to show incomplete combustion of an alkane?

Back 7

Back (Definition)

Front 8

Equation to show how sulfur dioxide is removed from glue gases?

Back 8

SO2 + CaO -> CaSO3

(Can also use CaCO3)

• calcium sulfite is used to make calcium sulfate for plasterboard

Front 9

Halogenoalkanes contain a polar bond

Back 9

•

Front 10

The carbon-halogen bond enthalpy decides reactivity.

Fluoroalkanes undergo nucleophilic substitution more slowly than iodoalkanes.

Back 10

•

Front 11

NO and NO2 effects:

Back 11

NO

• toxic

• can form NO2

NO2

• toxic

• acidic

• form acid rain

Front 12

The two reactions in catalytic converters:

Back 12

Back (Definition)

Front 13

Ozone is formed naturally in the upper atmosphere

Back 13

•

Front 14

Why is ozone beneficial?

Back 14

Absorbs UV

Front 15

Equation to show the formation of ozone naturally (in the upper atmosphere) ?

Back 15

Back (Definition)

Front 16

How are chlorine free radicals formed in the upper atmosphere?

Back 16

UV radiation causes C-Cl bonds in chlorofluorocarbons (CFCs) to break

Front 17

What is a chlorofluorocarbon?

Back 17

A halogenoalkane molecule where all of the hydrogen atoms have been replaced by chlorine and fluorine atoms

Front 18

The formation of major and minor products in addition reactions of unsymmetrical alkenes.

Back 18

•

Front 19

How to IUPAC name an addition polymer?

Back 19

• write the name of the alkene monomer e.g. chloroethene

• put brackets around it e.g. (chloroethene)

• put poly in front

E.g. poly(chloroethene)

Front 20

Draw the repeating unit of an addition polymer?

Back 20

(Make sure to include trailing bonds)

Front 21

For addition polymers, repeating units are always two carbons long

Back 21

•

Front 22

Addition polymers are unreactive.

Back 22

•

Front 23

Plasticised PVC is much more flexible than rigid PVC

Back 23

•

Front 24

What allows yeast to produce ethanol?

Back 24

They have an enzyme

(Consider optimum rate and denaturation)

Front 25

The industrial production of ethanol by fermentation of glucose uses renewable resources

Back 25

•

Front 26

Conditions for the hydration of ethene?

Back 26

• steam (gaseous water)

• 330°C

• pressure (70 atm)

• solid phosphoric (V) acid catalyst

Front 27

Arguments for and against biofuels?

Back 27

For

• renewable energy source -> sustainable

• usually classed as carbon neutral

Against

• to be used as fuels -> engine modification

• problems where countries grow biofuel instead of feeding people

Front 28

Addition polymers can be produced without using monomers derived from crude oil

Back 28

Back (Definition)

Front 29

The principle behind infrared spectroscopy

Back 29

Bonds in a molecule absorb infrared radiation at characteristic wavenumbers (characteristic frequencies)

Front 30

Infrared spectroscopy can be used to find out how pure a compound is. How?

Back 30

Impurities produce extra peaks in the fingerprint region.

Front 31

Global warming is caused by a very similar mechanism to infrared spectroscopy.

How?

Back 31

• CO2, methane, water vapour (greenhouse gases) obviously all have bonds

• these bonds absorb infrared radiation

• they re-emit some infrared radiation back towards earth

• more greenhouse gases in the atmosphere is amplifying this effect

Front 32

Write an equation for the reduction of propanal to propan-1-ol?

Back 32

Back (Definition)

Front 33

Write an equation for the reaction of propanone with HCN? (Name the product)

Write an equation for the reaction of ethanal with HCN? (Name the product)

Back 33

Back (Definition)

Front 34

Racemic mixture

Back 34

• a mixture of equal amounts of enantiomers

Front 35

Bond length

c-c > c-c (In benzene) > c=c

Back 35

•

Front 36

Benzene ring -> planar

Back 36

•

Front 37

Condensation polymers are generally stronger and more rigid than addition polymers. Why?

Back 37

• condensation polymers are made up of chains containing polar bonds e.g. C-N and C-O. So as well as VDWs, they have permanent dipole-dipole forces and hydrogen bonds between polymer chains

Front 38

Uses of Nylon 6,6?

Back 38

• clothing

• carpet

• rope

Front 39

What is Kevlar used for?

Back 39

• Bulletproof vests

• lightweight sports equipment

Front 40

What is Terylene used for?

Back 40

• Plastic bottles

• clothing

Front 41

What are aromatic amines used for?

Back 41

• making dyes

Front 42

Amino acids can be separated and identified by thin-layer chromatography.

Back 42

•

Front 43

Describe 2 ways of locating amino acids on a chromatogram?

Back 43

Use locating agents, either:

• spray with ninhydrin

• ultraviolet light

Front 44

On a chromatogram, amino acids are identified by their ...?

Back 44

Rf values

Front 45

Enzymes have stereospecific active sites.

Back 45

•

Front 46

Chemists aim to design processes/pathways that:

Back 46

• do not require a solvent

• use non-hazardous starting materials

• have fewer steps

• have a high percentage atom economy

Front 47

What can chromatography be used for?

Back 47

To separate and identify components in a mixture.

Front 48

Types of chromatography?

Back 48

• Thin-layer (TLC)

• Column chromatography (CC)

• Gas chromatography (GC)

Front 49

Explain simply what TLC involves?

Back 49

A plate is coated with a solid and a solvent moves up the plate

Front 50

Explain simply what Column chromatography involves?

Back 50

A column is packed with a solid and a solvent moves down the column

Front 51

Explain simply what gas chromatography involves?

Back 51

A column is packed with a solid (or solid coated by a liquid) and a gas is passed through the column under high pressure at high temperature

Front 52

Separation depends on the balance between solubility in the stationary phase and retention by the stationary phase

Back 52

•

Front 53

In the different types of chromatography, retention times and Rf values are used to identify different substances

Back 53

•

Front 54

A mass spectrometer can be used to analyse the components separated by gas chromatography.

Back 54

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Front 55

Give the advantages and disadvantages of different methods of disposal of polymers?

Back 55

Landfill

• pros: cheap and easy, useful when the plastic is difficult to separate from other waste/not in sufficient quantities to make separation financially worthwhile/too difficult technically to recycle

• cons: requires lots of land, as the waste decomposes it can release methane a greenhouse gas, leaks can contaminate water supplies

Incineration

• pros: the heat released can generate electricity

• cons: the process needs to be carefully controlled to reduce the release of toxic gases (polymers containing chlorine can produce HCl when burnt), produces CO2 (contributes to global warming)

Recycle

• pros: reduces amount of waste going into landfill, it saves raw materials (oil), the cost of recycling plastics is lower than making the plastics from scratch), produces less CO2 than burning the plastic

• cons: technically difficult, more expensive than burning/landfill, you often can’t remake the plastic you started with, the plastic can be easily contaminated during the recycling process

Front 56

Describe the process of recycling polymers?

Back 56

1) the polymers are separated and sorted

Then there are two types:

• some plastics can be melted and remoulded

• some plastics can be cracked into monomers -> can be used to make more plastics or other chemicals

Front 57

Amino acids are amphoteric. Have both acidic and basic properties.

Basic amino group

Acidic carboxyl group

Back 57

•

Front 58

Define - isoelectric point (of an amino acid)?

Back 58

The pH where the average overall charge on the amino acid is zero

Front 59

Equation for the hydration of ethene?

Back 59

CH2=CH2(g) + H2O(g) -> CH3CH2OH(l)

Front 60

In a condenser, water goes against the force of gravity. Why?

Back 60

• provides more efficient cooling

• prevents back flow of water

Front 61

Equation to show how tollens reagent and equation to show how Fehling’s solution work.

Back 61

Look up

Front 62

What will you observe in the Fehling’s solution test?

Back 62

Blue Cu2+ solution -> red Cu2O ppt

Front 63

What happens if air is present in fermentation of glucose by yeast?

Back 63

Ethanol oxidised to ethanoic acid